Filmmaker Michael Epstein couldn’t believe his luck when Yoko Ono gave him access to hours of forgotten footage of her life with John Lennon.

The singer and performance artist decided it was time to show fans the home videos shot at the couple’s Tittenhurst Park home in England and in New York in 1970 and 1971, and called in Epstein to sort through it. The result is John & Yoko: Above Us Only Sky, which will air on America’s A&E network next week.

The thrilled director is still pinching himself after realizing he had his hands on Lennon’s mythical Clock movie and unseen footage of George Harrison performing with Lennon.

“Yoko realized there was all this material that had been shot that nobody had ever seen,” he tells WENN. “I thought I had seen everything and I thought I knew the story, but I remember seeing this footage for the first time and just being blown away…

“I open the film with John at an upright piano playing out the chords to How, which is on the Imagine album, and the camera pulls back and you see it’s George Harrison who is playing. George is not credited on the album for playing How. Nobody has ever seen this material before.

“There’s also footage of John and Yoko in 1971, holed up at the St. Regis Hotel in New York. John made an experimental film called Clock, which is him sticking the camera in front of the mirror and hanging out. He’s just sitting on the couch with his guitar, singing songs. You see the real John as a fly on the wall.

“That footage of Clock had only been rumoured to exist. I don’t think anybody had ever physically seen it.”

Epstein was also given access to video of Lennon and Ono “mucking about” and “having breakfast at Tittenhurst” while making Imagine, but he admits not all the footage was easy to watch — he has also included video of JLennon meeting Vietnam veteran Curt Claudio.

“He started to write to John from the V.A. Hospital in San Francisco and then went to England because he believed John was speaking to him directly though his music and, at different times, he believed he was John,” the director explains.

“It’s a scary, terribly sad piece of footage because we all know how John’s story ends. Curt came to Tittenhurst and John just went to meet him. He met him with an open heart and had no anger that he was invading his space. Then he invites him in. We put in every single frame we could of it.”

Lennon was shot dead by obsessed fan Mark David Chapman in December 1980.